| 摘要 |
<P>PROBLEM TO BE SOLVED: To identify a failed hydraulic switch quickly and clearly, if there is any. <P>SOLUTION: The hydraulic switch is judged to be in a failure state when the ON-state of a hydraulic switch continues until a timer value TB reaches the prescribed value Tb by detecting the condition of the hydraulic switch when the ignition switch is turned on before engine starting in addition to the confirmation processing of the hydraulic switch condition during driving the car. The hydraulic switch can be judged to be in the normal or failure state with high accuracy because the judgement is made in a certain condition that the oil pressure is not generated before engine starting, irrespective of any range of an automatic transmission. The hydraulic switch of the frictional element connected in the D range can be surely judged to be in the normal or failure state only with a D range is normal or failure by detecting the condition of the hydraulic switch when a shift from the D range to the P, R, N range is made during driving the car. <P>COPYRIGHT: (C)2007,JPO&INPIT |
